1. Field of the Invention
This invention relates generally to semiconductor manufacturing, and, more particularly, to a method and apparatus for integrating a simulation environment into a semiconductor manufacturing process environment.
2. Description of the Related Art
The technology explosion in the manufacturing industry has resulted in many new and innovative manufacturing processes. Today""s manufacturing processes, particularly semiconductor manufacturing processes, call for a large number of important steps. These process steps are usually vital, and therefore, require a number of inputs that are generally fine-tuned to maintain proper manufacturing control.
The manufacture of semiconductor devices requires a number of discrete process steps to create a packaged semiconductor device from raw semiconductor material. The various processes, from the initial growth of the semiconductor material, the slicing of the semiconductor crystal into individual wafers, the fabrication stages (etching, doping, ion implanting, or the like), to the packaging and final testing of the completed device, are so different from one another and specialized that the processes may be performed in different manufacturing locations that contain different control schemes.
Among the factors that affect semiconductor device manufacturing are wafer-to-wafer variations that are caused by manufacturing problems that include start-up effects of manufacturing machine tools, memory effects of manufacturing chambers, and first-wafer effects. Furthermore, changes in one aspect of a manufacturing processing step can lead to adverse effects during another portion of the manufacturing processing step.
Generally, a set of processing steps is performed on a lot of wafers on a semiconductor manufacturing tool called an exposure tool or a stepper. The manufacturing tool communicates with a manufacturing framework or a network of processing modules. The manufacturing tool is generally connected to an equipment interface. The equipment interface is connected to a machine interface to which the stepper is connected, thereby facilitating communications between the stepper and the manufacturing framework. The machine interface can generally be part of an advanced process control (APC) system. The APC system initiates a control script, which can be a software program that automatically retrieves the data needed to execute a manufacturing process. The input parameters that control the manufacturing process are revised periodically in a manual fashion. As the need for higher precision manufacturing processes is required, improved methods are needed to revise input parameters that control manufacturing processes in a more automated and timely manner. Furthermore, wafer-to-wafer manufacturing variations can cause non-uniform quality of semiconductor devices.
A known technique for evaluating the acceptability of the photolithography and other processes involves measuring critical dimensions or other parameters after the process is performed. Many times, these measurements lead to manufacturing solutions that can only be implemented during a subsequent manufacturing process. A more efficient means of predicting possible errors based upon adjustments made upon manufacturing control parameters (for a variety of steps performed by a plurality of processing tools) can lead to higher production accuracy.
The present invention is directed to overcoming, or at least reducing the effects of, one or more of the problems set forth above.
In one aspect of the present invention, a method is provided for implementing a control simulation environment into a manufacturing environment. A process task is defined. A process simulation function is performed to produce simulation data corresponding to the process task. The simulation data is integrated with a process control environment for controlling a manufacturing process of a semiconductor device.
In another aspect of the present invention, a system is provided for implementing a control simulation environment into a manufacturing environment. The system of the present invention comprises: a computer system; a manufacturing model coupled with the computer system, the manufacturing model being capable of generating and modifying at least one control input parameter signal; a machine interface coupled with the manufacturing model, the machine interface being capable of receiving process recipes from the manufacturing model; a processing tool capable of processing semiconductor wafers and coupled with the machine interface, the first processing tool being capable of receiving at least one control input parameter signal from the machine interface; a metrology tool coupled with the first processing tool and the second processing tool, the metrology tool being capable of acquiring metrology data; a metrology data analysis unit coupled with the metrology, the metrology data analysis unit being capable of organizing the acquired metrology data; and a simulation environment coupled to the metrology data analysis unit and the computer system, the simulation environment capable of producing simulation data for controlling manufacturing of semiconductor wafers.